The present invention relates to a bobbin holder of a winder.
In FIG. 1 there is shown a prior art bobbin holder comprising a bobbin holding disk 1 (mainly for a cone bobbin) or projection (mainly for a parallel bobbin), a rotary shaft 2, balls 3 and 4, an outer race 5 and a bushing 6. The rotary shaft 2 is pressed and fitted into a hole in the bobbin holder 1 or otherwise formed integral therewith, and the balls 3 make up a deep-groove ball bearing so that the thrust load may be taken by it to some extent, but it cannot carry heavy thrust loads. Furthermore because of the limited space, the balls 3 and 4 with only a small diameter are used. The yarn is taken around the bobbin at a constant peripheral speed so that the rotational speed of the bobbin holder is as high as 3,000 r.p.m. when the spinning is started and the weight of yarn taken on the bobbin is as heavy as 1.5 kilograms at the end of the winding. These loads are concentrated on the bearings so that the bearings are subjected to severe wear and abrasion and consequently their service life is very short. Moreover, a three-stepped bore consisting of a small-diameter bore portion 6a for receiving therein the lower end portion of the shaft 2, an intermediate-diameter portion 6b for receiving the outer race 5 and a large-diameter portion 6c for receiving therein a boss 1' of the bobbin holding plate 1 must be bored or otherwise formed in the bushing 6, and the dimensions of these bore portions are limited. Because of these complex configurations, a large number of steps is required for the fabrication of the bushing 6.